This is a question Josh asked me via email:

If someone is talking and you hide at a nearby place or you are passing by and you hear what they are discussing. Is there a word for that you hiding to hear what you did?

I would say that’s ‘eavesdropping’. Is that right?

TOEFL listening lectures: Why is Carlos Finlay significant?[YSaerTTEW443543]

If you are not trying to hear what they are discussing, but you hear it anyway, we say you have “overheard” what they are discussing.

If you put your ear to the door somewhere or hide behind the people and listen – or better yet, do what my friend did when we were children and hang a microphone in the center of a saucer sled and point the sled at people half a block away – then you are eavesdropping.

Everything depends on whether you were trying to hear them or not.